The goal of the current proposal is to obtain funds for the purchase of a high-resolution ultrasound micro- imaging system designed specifically for non-invasive small animal research. The Visualsonics Vevo 770 offers spatial resolution down to 30 microns, a significant advantage over all other commercially available systems designed for human use. The instrument will initially support ten projects, each directed by an established investigator and funded by NIH grants. These projects focus on in vivo models of cardiovascular disease. The needs of these projects are varied and include ECHO cardiography, vascular wall structural imaging, pulse Doppler flow measurements, and microbubbles for quantification of intrarenal blood flow and tracking biomarkers of vascular inflammation. In addition to the basic imaging unit, computer, and software, there are several accessories that are required. These include 1) a variety of scan heads that are specific for the various applications used in the proposed studies: rat/mouse abdominal (RMV-703), mouse abdominal &small mouse cardiac (RMV-706), adult mouse cardiac (RMV-707B), and rat cardiac (RM-710B), 2) pulse wave Doppler with capture and analysis software, 3) 3D acquisition and visualization motor and control software, and 4) in vivo rail system for maintaining body temperature, scan head positioning, ECG and respiration monitoring. The different scan heads are required because of the different needs of each project. Similarly, several projects need to take advantage of the pulse Doppler capabilities and/or the 3D visualization. Finally, all projects will need to use the in vivo rail system for reducing movement artifacts and maintaining health of the animals during imaging. This instrumentation gives us the ability to quantitate blood flow and vascular structure without surgical intervention and over prolonged periods of time. This represents a major advance in our capabilities to phenotype various animal models and explore novel mechanisms related to the pathogenesis of cardiovascular disease. The ability to use this methodology in both rats and mice is particularly important given the historical use of rats in cardiovascular research and the growing use of genetically manipulated mice. The goals of the various projects include but are not limited to determining: 1) changes in medullary blood flow that control of sodium excretion in salt-dependent models of hypertension;2) the impact of obesity and insulin resistance on hindlimb and endocrine organ perfusion in metabolic disease;3) how the balance of excitatory and inhibitory synaptic transmission in the hypothalamic paraventricular nucleus is influenced in heart failure;4) long-term changes in renal blood flow produced by angiotensin II, P2X1, and A1 receptors;5) whether NOS1 contributes to regulation of vascular remodeling and control of sodium excretion;6) whether platelet secretion is a key mediator of thrombotic and inflammatory processes after acute injury and during atherosclerosis;7) if the biological clock gene regulates vascular remodeling in stenotic arteries. PUBLIC HEALTH RELEVANCE: The goal of the current proposal is to obtain funds for the purchase of a high-resolution ultrasound micro imaging system, Visualsonics Vevo 770, designed specifically for visualizing anatomical structures, vascular dynamics, and cardiac function within living rats and mice without any surgical intervention. The ability to conduct non-invasive procedures in rodents similar to what is done in humans will provide a distinct advance in our research program that is highly focused in the area of cardiovascular translational research.